4-(1-Methylethyl)aniline

4-(1-メチルエチル)アニリン

[CAS No. 99-88-7]

4-Isopropylaniline/p-Isopropylaniline

4-イソプロピルアニリン/p-イソプロピルアニリン

Molecular formula: C9H13N Molecular weight: 135.21

ABSTRACT

4-(1-Methylethyl)aniline was studied for oral toxicity in rats of both sexes in a single dose toxicity test at doses of 700, 910, 1183, 1538 and 2000 mg/kg. This revealed an LD50 value of 985 mg/kg for both sexes.

4-(1-Methylethyl)aniline was studied for oral toxicity in rats in an OECD combined repeat dose and reproductive/developmental toxicity screening test at doses of 0, 6, 20 and 60 mg/kg/day.

In the repeat dose toxicity, one female was found dead in the 60 mg/kg group at day 25 of gestation. Anemic eyeballs and salivation were observed in the 20 mg/kg or more groups in both sexes and pallor in the 60 mg/kg group was noted in females during the gestation period. Body weight gain showed a tendency for decrease in the 20 mg/kg or more groups in males and in the 60 mg/kg group in females during the gestation period. Food consumption was decreased in the 60 mg/kg group in males during the early administration period. Hematology of male animals revealed methemoglobin increase in the 20 mg/kg or more groups. Furthermore, HCT, HGB, RBC and MCHC was decreased and MCV, MCH, PLT and RC increased in the 60 mg/kg group. Increases in spleen weights in the 60 mg/kg males and in 20 mg/kg or more females and increases in liver weights in males given 20 mg/kg or more and in 60 mg/kg females were observed.

As gross necropsy findings, blackening and enlargement of spleen were observed in the 20 mg/kg or more groups in both sexes. As histological findings, increases of hematopoiesis in bone marrow, congestion, deposits of pigment and extramedullary hematopoiesis in the spleen were observed in 20 mg/kg or more groups in both sexes. In the liver, extramedullary hematopoiesis was observed in 60 mg/kg males and in the 20 mg/kg or more groups in females. Deposits of pigment and hypertrophy of hepatocytes were observed in both sexes receiving 60 mg/kg of the test substance. The incidence or degree of these findings in treatment groups were greater than in the control group.

On the basis of these findings, the NOEL for repeat dose toxicity in parent animals of both sexes is considered to be 6 mg/kg/day.

In terms of reproductive/developmental toxicity, no adverse effects were observed in estrus cycle, copulation and fertility results, findings for delivery and duration of gestation period in any treatment groups. With regard to the effects on neonates, body weights of pups in both sexes and viability on day 4 of lactation in the 60 mg/kg group were decreased.

On the basis of these findings, NOELs for reproductive/developmental toxicity are considered to be 60 mg/kg/day for parent animals and 20 mg/kg/day for the F1 generation, respectively.

4-(1-Methylethyl)aniline was mutagenic in Salmonella typhimurium TA100 and TA1535 with an exogenous metabolic activation system.

Genotoxicity of 4-(1-methylethyl)aniline was studied by chromosomal aberration test in cultured Chinese hamster lung (CHL/IU) cells. 4-(1-Methylethyl)aniline did not induce structural chromosomal aberrations and polyploidy up to the highest dose for which it was possible to analyse chromosomes an continuous treatment and on short-term treatment with and without an exogenous metabolic activation system.

SUMMARIZED DATA FROM THE STUDIES

1. Single Dose Oral Toxicity 1)

Purity

:

99.27 wt%

Test species/strain

:

Rat/Crj: CD(SD)

Test method

:

OECD Test Guideline 401

Route

:

Oral (gavage)

Doses

:

700, 910, 1183, 1538, 2000 mg/kg

Number of animals/group

:

Males, 5; females, 5/group

Vehicle

:

Corn oil

GLP

:

Yes

Test results:

Deaths of both sexes occurred in the 910 mg/kg and higher groups. In animals in all the groups, abnormal gait, decreased spontaneous motor activity and salivation were observed in both sexes. Lachrymation and adoption of a prone, lateral position and/or hunched back position were observed in both sexes receiving 910 mg/kg or more. Moreover, hair soiling and abdominal distension were observed in some groups.

Males, 48 daysFemales, from 14 days before mating to day 3 of lactation

Terminal kill

:

Males, day 48Females, day 4 of lactation

GLP

:

Yes

Test results:

<Repeat dose toxicity>

In the repeat dose study, one female rat was found dead in the 60 mg/kg group at day 25 of gestation. Anemic eyeballs and salivation were observed in the 20 mg/kg or more groups in both sexes and pallor in the 60 mg/kg group was observed in females during gestation period. Body weight gain showed a tendency to decrease in the 20 mg/kg or more groups in males and in the 60 mg/kg females during the gestation period. Food consumption was decreased in the 60 mg/kg males during the early administration period. Hematology of male animals revealed methemoglobin increase in the 20 mg/kg or more groups.

Furthermore, HCT, HGB, RBC and MCHC were decreased and MCV, MCH, PLT and RC increased in the 60 mg/kg group. Increases in spleen weights in 60 mg/kg males and in 20 mg/kg or more females and increases in liver weights in males in 20 mg/kg or more groups and in females in 60 mg/kg group were observed. As gross findings, blackening and enlargement of the spleen were observed in the 20 mg/kg or more groups in both sexes. As histological findings, increase of hematopoiesis in bone marrow, congestion, deposits of pigment and extramedullary hematopoiesis in the spleen were observed in both sexes of the 20 mg/kg or more groups. In the liver, extramedullary hematopoiesis was observed in 60 mg/kg males and in 20 mg/kg or more females, and deposits of pigment and hypertrophy of hepatocytes were observed in both sexes receiving 60 mg/kg of the test substance. The incidence or degree of these findings in treatment groups were greater than in the control group.

On the basis of these findings, the NOEL for repeat dose toxicity in parent animals of both sexes was considered to be 6 mg/kg/day.

<Reproductive and developmental toxicity>

As for reproductive ability of parent animals, no adverse effects of the test substance were observed in either sex.

With regard to the effects on neonates, body weights of pups in both sexes and viability on day 4 of lactation in the 60 mg/kg group were decreased.

On the basis of these findings, NOELs for reproductive/developmental toxicity were considered to be 60 mg/kg/day for parent animals and 20 mg/kg/day for the F1 generation, respectively.